An analyzing device contains a feed passage having a microchannel structure for transporting a liquid to be tested from a sample feed opening to a measuring chamber, a separating chamber containing a reagent reacting with components to be tested, the measuring chamber connected to the separating chamber via a first branch, and a reservoir connected to the separating chamber via a second branch.
The analyzing device is rotated or pivoted about a rotating shaft after collecting a liquid to be tested from the sample feed opening. Thus, the liquid in a mixing cavity is mixed and centrifuged, specific components are separated by the reagent in the separating chamber, the liquid treated in the separating chamber is transported to the measuring chamber, and then the analyzing device is used for reading for accessing the liquid in the measuring chamber.